1. Field of the Invention
The present invention relates to a hot-air fabric welder for waterproofing tape which completely waterproofs a seam portion by heat-welding a synthetic resin tape on the seam portion of a product made of a waterproof sheet such as a tent, raincoat, jumper, hat or ski suit, and more specifically to a hot-air fabric welder for waterproofing tape for manufacturing both a straight-line heat-welded portion and an arc-shaped heat-welded portion through selective use of a flat roller portion or a tapered roller portion in opposition to the upper roller, by configuring the appropriate part of the lower roller unit in opposition to the upper roller.
2. Related Prior Art
In general, for products that need waterproofing such as a tent, raincoat, jumper, hat or ski suit, complete waterproofing is possible for the waterproof sheet, but pinholes are perforated along the seam in the process of sewing it. Therefore, for waterproofing of the perforated part, complete waterproofing treatment is done by affixing a synthetic resin tape to the seam portion by heat welding.
At this time, a wide or narrow tape of synthetic resin should be used depending on the characteristics of the product or the width of the seam and in relation to this, a wide or narrow support roller also should be utilized for complete waterproofing treatment of the product.
But because it is not possible for a conventional tape welder to utilize a wide or narrow support roller depending on the width of the synthetic resin tape, it has been used as it is. Further, an extra tape welder, such as a tape welder having a wide support roller or a tape welder having a narrow support roller, needs to be provided depending on the width of the synthetic resin tape. Because of that, using a tape welder of one kind regardless of the width of the synthetic resin has many problems such as a high rejection rate of the product or an enormous cost if different tape welders are provided according to the width of the synthetic resin tape.
However, since the conventional hot-air fabric welder for waterproofing tape has flat upper roller and lower roller units, it is possible to heat-weld only a straight seam with a waterproof tape. Because it is possible to process the roller only in a straight line due to the characteristics of the flat roller, it is possible to heat-weld only a straight waterproof tape to the seam of various products made of waterproof fabric. Therefore, various constraints limit the process of heat-welding the waterproof tape to a seam having various curve shapes such as a neck portion, shoulder, chest and sleeve, when using a conventional hot air welder. In order to produce products made of waterproof sheet of synthetic resin with curved surfaces such as a tent, raincoat, jumper, hat or ski suit, the worker makes the product by putting it in by force and rotating it along the relevant curvature by force, so creases occur in the welding portion of the waterproof tape due to overlapping of the product fabric or the waterproof tape, which causes the appearance to be not beautiful and lowers the marketability of the product.